PvE is a game of efficiency; you want to ramp up into more power wells and more orbs as quickly as possible. Against another player, this is unlikely; your expenditures need to be matched against theirs

Conversely, do not let your opponent trap you in T1 or T2. E.g., use the time between when they start building a new orb and when they have enough power to build new units of that tier to attack and hopefully get them to lose power, sure. But do not spend so much power on that attack that you yourself cannot afford a new orb.

If your opponent tries a hard rush, don't expand. Wait and counter the rush, then expand. You will need the power to counter the rush.

If your small units are being knocked around, build medium units instead.

Don't build walls you don't need. You will have less power to use.

Don't let your opponent build a wall that is near your orbs or power wells.

Having power in your pool is better than having a lot of units standing around doing nothing.

Summon just one unit at the start, unless you are rushing. If you need more later, you can summon them later.

The biggest and meanest looking creature doesn't always win. Don't rely solely on XL creatures to win, and don't give up if they are used against you. They can be beaten.

T4 is rarely used in PvP, you are better off taking them out of your deck. At most, keep no more than one.

You can try to capture the central monument. If you do that, you can quickly send fresh units to the battle, but it isn't always the best strategy. On some maps, the central monument is highly vulnerable to attack.

Watch out for hills, the enemy can use the high ground against you.

A Dazed creature is worth only half a creature, avoid sending them into battle.

See Also

Circadia's PvP guide - An extensive PvP guide for new players or players looking to improve, specifically focusing on 1v1 PvP. It deals with many of the mechanics of BattleForge and offers insights into strategies and counters.